During the examination of an abnormal specimen of the Scottish Red Deer (Cervus elaphus) in the winter of 1930, my colleague, Mr. W. C. Miller, M.R.C.V.S., discovered several specimens of a bursate nematode lying on the connective tissue between the latissimus dorsi and the external intercostal muscles. Struck by the unusual habitat of such a worm, search was subsequently made in similar situations in other deer, and in two animals the same parasite was found.